Adler debuted as something of a boy wonder (Dialectic published at 25, for instance), but the stir he created during the `30's, especially with Hutchins at Chicago, eventually hardened into editorial-administrative success, solid as a sideboard, with the Great Books of the Western World project, the Syntopicon, and similar foundation-type pursuits. The book here, based on the Encyclopedia Britannica Lectures he delivered at Chicago last year, starts off on a very glum note indeed. Adler deems philosophy neither a rewarding nor challenging profession for the young, and that its present bifurcated state--Anglo-American linguistic analysis high-hatting continental existentialism, and vice-versa- will lead to ruin. Thus while gazing perhaps towards C.P. Snow, he sets down five conditions which modern day philosophy must fulfill if it is to be taken as seriously as science. Then he tackles related problems of methodology, the ""Is-Ought"" test, the ""Mixed Question"" test, as well as including incidental examinations of Popper, Heisenberg, James, etc., and reserving three chapters for the glories and fallacies of Ancient, Medieval and post-Cartesian philosophy. His position, which is, in C.I. Lewis' phrase, that ""proof, in philosophy, can be nothing more at bottom than persuasion,"" is nevertheless very subtly and at the same time fundamentally connected with the empirical outlook and with ""philosophy as a public enterprise."" It is too circuitous for easy capsulation, but Adler gives it a fine pedagogical run.